From 6047d578f8faf595002382750719b96579d4b385 Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Tue, 10 Mar 2020 12:19:24 -0400
Subject: [PATCH 1/3] fully randomize hop selection

---
 llarp/nodedb.cpp | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/llarp/nodedb.cpp b/llarp/nodedb.cpp
index 6c2282a1b..a1a5cd8ea 100644
--- a/llarp/nodedb.cpp
+++ b/llarp/nodedb.cpp
@@ -537,17 +537,16 @@ llarp_nodedb::select_random_hop(const llarp::RouterContact &prev,
     return false;
   if(!N)
     return false;
-  llarp_time_t now = llarp::time_now_ms();
 
-  auto itr   = entries.begin();
-  size_t pos = llarp::randint() % sz;
+  auto itr         = entries.begin();
+  const size_t pos = llarp::randint() % sz;
   std::advance(itr, pos);
-  auto start = itr;
+  const auto start = itr;
   while(itr == entries.end())
   {
     if(prev.pubkey != itr->second.rc.pubkey)
     {
-      if(itr->second.rc.addrs.size() && !itr->second.rc.IsExpired(now))
+      if(itr->second.rc.IsPublicRouter())
       {
         result = itr->second.rc;
         return true;
@@ -560,7 +559,7 @@ llarp_nodedb::select_random_hop(const llarp::RouterContact &prev,
   {
     if(prev.pubkey != itr->second.rc.pubkey)
     {
-      if(itr->second.rc.addrs.size() && !itr->second.rc.IsExpired(now))
+      if(itr->second.rc.IsPublicRouter())
       {
         result = itr->second.rc;
         return true;
@@ -583,17 +582,16 @@ llarp_nodedb::select_random_hop_excluding(
   {
     return false;
   }
-  llarp_time_t now = llarp::time_now_ms();
 
-  auto itr   = entries.begin();
-  size_t pos = llarp::randint() % sz;
+  auto itr         = entries.begin();
+  const size_t pos = llarp::randint() % sz;
   std::advance(itr, pos);
-  auto start = itr;
+  const auto start = itr;
   while(itr == entries.end())
   {
     if(exclude.count(itr->first) == 0)
     {
-      if(itr->second.rc.addrs.size() && !itr->second.rc.IsExpired(now))
+      if(itr->second.rc.IsPublicRouter())
       {
         result = itr->second.rc;
         return true;
@@ -606,7 +604,7 @@ llarp_nodedb::select_random_hop_excluding(
   {
     if(exclude.count(itr->first) == 0)
     {
-      if(itr->second.rc.addrs.size() && !itr->second.rc.IsExpired(now))
+      if(itr->second.rc.IsPublicRouter())
       {
         result = itr->second.rc;
         return true;

From 69126c67df7dafb367caeef30e55fbf7eae2050f Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Wed, 11 Mar 2020 10:08:53 -0400
Subject: [PATCH 2/3] code dedup

---
 llarp/nodedb.cpp | 41 ++---------------------------------------
 1 file changed, 2 insertions(+), 39 deletions(-)

diff --git a/llarp/nodedb.cpp b/llarp/nodedb.cpp
index a1a5cd8ea..38d0ca3f7 100644
--- a/llarp/nodedb.cpp
+++ b/llarp/nodedb.cpp
@@ -529,45 +529,8 @@ bool
 llarp_nodedb::select_random_hop(const llarp::RouterContact &prev,
                                 llarp::RouterContact &result, size_t N)
 {
-  llarp::util::Lock lock(access);
-  /// checking for "guard" status for N = 0 is done by caller inside of
-  /// pathbuilder's scope
-  size_t sz = entries.size();
-  if(sz < 3)
-    return false;
-  if(!N)
-    return false;
-
-  auto itr         = entries.begin();
-  const size_t pos = llarp::randint() % sz;
-  std::advance(itr, pos);
-  const auto start = itr;
-  while(itr == entries.end())
-  {
-    if(prev.pubkey != itr->second.rc.pubkey)
-    {
-      if(itr->second.rc.IsPublicRouter())
-      {
-        result = itr->second.rc;
-        return true;
-      }
-    }
-    itr++;
-  }
-  itr = entries.begin();
-  while(itr != start)
-  {
-    if(prev.pubkey != itr->second.rc.pubkey)
-    {
-      if(itr->second.rc.IsPublicRouter())
-      {
-        result = itr->second.rc;
-        return true;
-      }
-    }
-    ++itr;
-  }
-  return false;
+  (void)N;
+  return select_random_hop_excluding(result, {prev.pubkey});
 }
 
 bool

From 9cdc7f498d07e12e8f9f6bf897ee7ca0e4bf4787 Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Wed, 11 Mar 2020 10:12:29 -0400
Subject: [PATCH 3/3] remove dead code

---
 llarp/nodedb.cpp | 7 -------
 llarp/nodedb.hpp | 4 ----
 2 files changed, 11 deletions(-)

diff --git a/llarp/nodedb.cpp b/llarp/nodedb.cpp
index 38d0ca3f7..5f78f84d5 100644
--- a/llarp/nodedb.cpp
+++ b/llarp/nodedb.cpp
@@ -525,13 +525,6 @@ llarp_nodedb::select_random_exit(llarp::RouterContact &result)
   return false;
 }
 
-bool
-llarp_nodedb::select_random_hop(const llarp::RouterContact &prev,
-                                llarp::RouterContact &result, size_t N)
-{
-  (void)N;
-  return select_random_hop_excluding(result, {prev.pubkey});
-}
 
 bool
 llarp_nodedb::select_random_hop_excluding(
diff --git a/llarp/nodedb.hpp b/llarp/nodedb.hpp
index 90c959a5d..90790e460 100644
--- a/llarp/nodedb.hpp
+++ b/llarp/nodedb.hpp
@@ -154,10 +154,6 @@ struct llarp_nodedb
   bool
   select_random_exit(llarp::RouterContact &rc) EXCLUDES(access);
 
-  bool
-  select_random_hop(const llarp::RouterContact &prev,
-                    llarp::RouterContact &result, size_t N) EXCLUDES(access);
-
   bool
   select_random_hop_excluding(llarp::RouterContact &result,
                               const std::set< llarp::RouterID > &exclude)